(1) Field of the Invention
The present invention relates to roofing tiles.
(2) Description of Related Art
The art of roofing tiles extends back over centuries involving a variety of media, such as fired clay, slate, and wood shingles. In general, tiles can be formed with a variety of shapes. For example, rectangular tiles arranged in overlapping rows are a common roofing style. Some styles include curves or angles on exposed segments and supporting areas that give the tile a three-dimensional look on a flat roof. These tiles can be formed of fired clay, cement, metal, plastics and composites.
Some tiles are configured with a diamond shape in which the high point to low point axis of the diamond extends in a direction generally perpendicular to the roof line. Diamond shaped tiles involve somewhat more complex arrangements for securing and overlapping the tiles than do straightforward rectangular tiles. One such type of rectangular tile includes a generally diamond shaped flat main surface having upwardly turned flanges along its upper two diamond edges and downwardly turned flanges along its lower two diamond edges. The flanges of this tile extend in a perpendicular relation to the main surface. Considering two vertically spaced upper and lower rows of tiles according to such arrangement, the downwardly facing flanges along the lower edges of the tiles in the upper row hook over the upwardly facing flanges along the upper edges of the tile in the lower row, and connector pins are driven into the underlying roof or laths through appropriately positioned openings through the tiles.
While tiles of the prior art type, as previously described, are generally satisfactory, certain disadvantages are associated with such a structure. The use of flanges which contact surfaces of different tiles essentially at right angles tends to give a rather “blocky” or abrupt appearance to the assembled groups of tiles rather than a smooth flowing transition. The essentially perpendicular flange relationships would tend to interfere with laminar flow of wind over the roof, which creates eddies and turbulence with increased wind resistance. In general, wind resistance is undesirable in a roofing system due to increases in wind noise and, in severe wind conditions over time, can contribute to the earlier loosening of tiles and reduction of roof life. Reducing the wind resistance of a tile system and providing a good means of attachment to the roof deck provide better protection from high winds. Reducing wind resistance herein has the same meaning as increasing resistance to wind effects.
In addition, this prior art type of tile fails to compensate for structural variations of the tiles due to imprecise manufacturing techniques involved in tile making. These structural variations of the tiles can lead to difficulties in fitting tiles together due to interference fits and instances of roofers installing tiles imprecisely on the roof laths such that they are to some degree misaligned. Sometimes, the roof deck may not be perfectly flat which contributes to the alignment problem.
Another problem that can arise with tiles of this character is in connection with water as it falls and runs down the exposed surfaces of the tiles. The effect of wind driven rain can cause water to run under the flanges and flow in the channels defined by the space between an upper flange and a lower flange placed directly over it. While such water movement cannot be entirely avoided, there should be ways to reduce the opportunity for such channeled water to pass through the roof tiles onto the underlying structure.
Labor cost is a significant portion of the total cost of a new roof or roof replacement. A tile which covers more roof space will have faster installation times and lower labor costs associated with it. A tile with multiple, repeating patterns covers more roof than a tile with one pattern, where the patterns are of a similar size.